Suggestion: IfFileInUse

Hi there!

Above you see the thing I'm really missing from NSIS. I know I could do it with a little *hard* coding (at least for me), but it would be much better if I could use this function like this:

IfFileInUse file_to_check_for jump_if_inuse [jump_otherwise]

Just like the IfFileExists function. Actually the two function should be combined. I imagine the code (the *real* code like this):

function IfFileInUse(F: PChar): Boolean;

begin

  Result := False; //Initial result

  if FileExists(F) then //Check if file exists, and if so, then check whether it's in use

    Result := CreateFile(F, GENERIC_WRITE, 0, nil, OPEN_EXISTING, 0, 0) = INVALID_HANDLE_VALUE;

end;

Sorry, but since I only know Delphi Pascal my imagination can't do better either 😉

Best regards,
gLes

It's not hard coding at all:

ClearErrors

FileOpen $0 "path" "a"

FileClose $0

IfErrors locked notlocked

Doh! But wouldn't it be easier to do it my way?🙂

That will increase the overhead. This is easy enough (if you want to make it even easier, create a macro).

How that look like?🙂

!macro IfFileInUse FILE GOTONOTLOCKED GOTOLOCKED



ClearErrors



Push $R0



  FileOpen $R0 "${FILE}" "a"

  FileClose $R0



Pop $R0



IfErrors "${GOTONOTLOCKED}" "${GOTOLOCKED}"



!macroend

Usage:

!insertmacro IfFileInUse "c:\bla.txt" notlocked locked

Maybe I'll be cool if there is an instruction like the one:

IfFileExists 

Simple, easy and handy 🙂

Thx. 🙂

Lobo Lunar, that will increase the installer overhead. I think a macro is simple enough.

I don't think that's a reasonable solution to the problem at all. What happens if the file is a 30 MB data file?

How does the size affect anything?

And with LogicLib this is even easier.

!macro _FileInUse _a _b _t _f

  !insertmacro _LOGICLIB_TEMP

  ClearErrors

  FileOpen $_LOGICLIB_TEMP `${_b}` "a"

  FileClose $_LOGICLIB_TEMP

  IfErrors `${_t}` `${_f}`

!macroend



!define FileInUse `"" FileInUse`



${If} ${FileInUse} $INSTDIR\file

  DetailPrint "in use"

${EndIf}

It all depends on the system and file but in my experience the larger the file the longer fileopen takes, I just think there could be a better way.

oh I didn't see the "a" my bad